bot.py

import telebot
import numpy as np
import cv2
import imutils

TOKEN = "TOKEN"

bot = telebot.TeleBot(TOKEN)


@bot.message_handler(commands=['start', 'help'])
def send_welcome(message):
    bot.reply_to(message, "Hello, send me image and I`ll resize it to fit requirements of Telegram Stickers:\n\n \
image fits into a 512x512 square (one of the sides should be 512px and the other 512px or less).")


@bot.message_handler(func=lambda message: True)
def ask_photo(message):
    bot.send_message(message.chat.id, "Send me your image, please.")


@bot.message_handler(content_types=['photo'])
def photo(message):
    bot.send_message(
        message.chat.id, "Send me image without compression, please.")


@bot.message_handler(content_types=['document'])
def file(message):
    file_name = message.document.file_name
    file_id = message.document.file_name
    file_id_info = bot.get_file(message.document.file_id)
    downloaded_file = bot.download_file(file_id_info.file_path)
    filename = "img/" + file_name

    nparr = np.frombuffer(downloaded_file, np.uint8)
    image = cv2.imdecode(nparr, cv2.IMREAD_UNCHANGED)

    (h, w) = image.shape[:2]
    bot.send_message(message.chat.id, f"Height: {h}\nWidth: {w}")

    if h <= 512 and w <= 512:
        bot.send_message(
            message.chat.id, "your image fits into a 512x512 square")
    else:
        if h <= 512:
            resized = imutils.resize(image, width=512)
        elif w <= 512:
            resized = imutils.resize(image, height=512)
        else:
            # h > 512 and w > 512
            if h > w:
                resized = imutils.resize(image, height=512)
            else:
                resized = imutils.resize(image, width=512)
            
        cv2.imwrite("img/sticker.png", resized)
        res = open("img/sticker.png", 'rb')
        bot.send_document(message.chat.id, res)
        
        (h, w) = resized.shape[:2]
        bot.send_message(message.chat.id, f"Height: {h}\nWidth: {w}")

bot.polling()